[Experimental] Use :socket API

.github/workflows/test.yml

@@ -45,6 +45,8 @@ jobs:
             elixir: 1.14.5
           - otp: 26.0
             elixir: 1.15.4
+          - otp: 26.2
+            elixir: 1.16.3
     steps:
       - uses: actions/checkout@v2
       - uses: erlef/setup-beam@v1

lib/telemetry_metrics_statsd.ex

@@ -410,6 +410,10 @@ defmodule TelemetryMetricsStatsd do
 
   @doc false
   @spec udp_error(pid(), UDP.t(), reason :: term) :: :ok
+  def udp_error(_reporter, _udp, :eagain) do
+    :ok
+  end
+
   def udp_error(reporter, udp, reason) do
     GenServer.cast(reporter, {:udp_error, udp, reason})
   end

lib/telemetry_metrics_statsd/udp.ex

@@ -1,12 +1,10 @@
 defmodule TelemetryMetricsStatsd.UDP do
   @moduledoc false
 
-  defstruct [:host, :port, :socket]
+  defstruct [:socket]
 
   @opaque t :: %__MODULE__{
-            host: :inet.hostname() | :inet.ip_address() | :inet.local_address(),
-            port: :inet.port_number(),
-            socket: :gen_udp.socket()
+            socket: :socket.socket()
           }
 
   @type config :: %{
@@ -18,43 +16,53 @@ defmodule TelemetryMetricsStatsd.UDP do
   @spec open(config()) ::
           {:ok, t()} | {:error, reason :: term()}
   def open(config) do
-    opts = [{:active, false}]
-
-    opts =
-      Enum.reduce(config, opts, fn
-        {:host, {:local, _}}, opts -> [:local | opts]
-        {:inet_address_family, value}, opts -> [value | opts]
-        {_key, _value}, opts -> opts
-      end)
-
-    case :gen_udp.open(0, opts) do
-      {:ok, socket} ->
-        udp = struct(__MODULE__, Map.put(config, :socket, socket))
-        {:ok, udp}
-
-      {:error, _} = err ->
-        err
+    {domain, address} =
+      case config.host do
+        {:local, path} ->
+          {:local, %{family: :local, path: path}}
+
+        ip when tuple_size(ip) == 4 ->
+          {:inet, %{family: :inet, port: config.port, addr: ip}}
+
+        ip when tuple_size(ip) == 8 ->
+          {:inet, %{family: :inet6, port: config.port, addr: ip}}
+      end
+
+    with {:ok, socket} <- :socket.open(domain, :dgram),
+         :ok <- :socket.connect(socket, address) do
+      udp = struct(__MODULE__, Map.put(config, :socket, socket))
+      {:ok, udp}
     end
   end
 
   @spec send(t(), iodata()) :: :ok | {:error, reason :: term()}
-  def send(%__MODULE__{host: host, port: port, socket: socket}, data) do
-    case host do
-      {:local, _} ->
-        :gen_udp.send(socket, host, 0, data)
-
-      _ ->
-        :gen_udp.send(socket, host, port, data)
-    end
+  def send(%__MODULE__{socket: socket}, data) do
+    :socket.send(socket, data)
+    |> handle_send_result()
   end
 
   @spec update(t(), :inet.hostname() | :inet.ip_address(), :inet.port_number()) :: t()
-  def update(%__MODULE__{} = udp, new_host, new_port) do
-    %__MODULE__{udp | host: new_host, port: new_port}
+  def update(%__MODULE__{} = udp, _new_host, _new_port) do
+    #%__MODULE__{udp | host: new_host, port: new_port}
+    udp
   end
 
   @spec close(t()) :: :ok
   def close(%__MODULE__{socket: socket}) do
-    :gen_udp.close(socket)
+    :socket.close(socket)
+  end
+
+  defp handle_send_result({:error, :eagain}) do
+    # TODO: report packed drop?
+    :ok
+  end
+
+  defp handle_send_result({:error, :econnrefused}) do
+    # TODO: report packed drop?
+    :ok
+  end
+
+  defp handle_send_result(result) do
+    result
   end
 end

test/telemetry_metrics_statsd_test.exs

@@ -431,7 +431,7 @@
         new_udp != udp
       end)
 
-      assert :gen_udp.recv(udp.socket, 0) == {:error, :closed}
+      assert :socket.recv(udp.socket, 0) == {:error, :closed}
     end
   end
 
@@ -647,7 +647,7 @@
     assert_reported(socket, "http.requests:1|c")
   end
 
   test "IPv6 end-to-end test" do
     {socket, port} = given_udp_port_opened(:inet6)
     counter = given_counter("http.requests", event_name: "http.request")
 
@@ -659,7 +659,7 @@
   end
 
   describe "hostname resolution" do
     test "is performed on start by default" do
       counter = given_counter("http.request.count")
 
       reporter =
@@ -674,7 +674,7 @@
       assert udp.host == {127, 0, 0, 1}
     end
 
     test "Supports IPv6" do
       counter = given_counter("http.request.count")
 
       reporter =
@@ -690,7 +690,7 @@
       assert udp.host == {0, 0, 0, 0, 0, 0, 0, 1}
     end
 
     test "is not periodically repeated by default" do
       counter = given_counter("http.request.count")
 
       reporter =
@@ -714,7 +714,7 @@
       end
     end
 
     test "is periodically repeated if configured" do
       counter = given_counter("http.request.count")
 
       reporter =